libfreemkv/CHANGELOG.md

Changelog

[1.2.0] — 2026-06-28

Added

• Mux loss concealment — a logged gap still produces a decode-clean file. When a unit genuinely cannot be decrypted on the mux read path (a key the disc never yielded, after the rip's own decrypt-verify already failed loud and re-read), the mux no longer passes ciphertext downstream or emits a broken frame. The undecryptable aligned unit is concealed as NULL transport-stream packets (PID 0x1FFF, invisible to every real stream), and the codec layer drops forward to the next keyframe so no frame with a dangling reference reaches the muxer. An ffmpeg deep scan of the result is clean — no missing references, no partial frames. The loss is tallied and logged, never silently dropped, and the mux always completes. Audio and subtitle tracks have no cross-frame references, so only the directly-affected frames are dropped there. Decrypt-verify remains a rip gate (fail loud → re-read), never a mux gate.

Changed

• One hex parser. All hex parsing (keys, IDs, key-source inputs) routes through a single libfreemkv::hex parser instead of several ad-hoc decoders, so length/odd-nibble/invalid-digit handling is identical everywhere.
• Robust encrypted-unit sampling + a single MKB framing walker. Up-front AACS sampling tolerates content layouts that previously yielded too few encrypted units to resolve a key, and the Media Key Block is now walked by one framing routine shared across the in-band and out-of-band readers (no divergent record-stride logic). AACS resolution hardened around these paths.
• One reader, one DiscInputs. Disc::inputs() is now the single, complete source of a disc's AACS inputs (inf, MKB, VID, disc_hash, version), and read_aacs_inputs* returns the version alongside inf+MKB. Both the CLI and autorip resolve through Disc::inputs(); the duplicate out-of-band readers (autorip's key_files()/volume_id()) and the stale mapfile-VID read are removed. AACS file paths and the AACS major versions are now named constants (aacs::PATH_*, aacs::AACS_MAJOR_*, AacsVersion::major/from_major) so a fallback or stride change lives in exactly one place.

Fixed

• ISO mux no longer drops real video at content-fragment tails. A title's encrypted content can end mid-AACS-unit, with the disc zero-padding the rest of the 6144-byte aligned unit to the next fragment. The decrypt-verify demanded the TS sync byte on all 32 source packets, so it rejected such a tail unit over its legitimate padding — discarding the real video packets it contained. On a flawless rip this surfaced as a small phantom "loss" at mux (and, once retries were exhausted, a truncated MKV). Unit acceptance is now padding-aware: only packets whose source (pre-decrypt) bytes are non-zero must restore their TS sync; the zero padding is excluded from the check and emitted as clean zeros. A full content unit still requires all 32 (unchanged — no wrong-key relaxation), and a unit whose non-zero tail fails to decrypt is still rejected as a genuine bad read.
• ISO online key resolution now sends the Media Key Block. Capturing a disc's AACS inputs at scan read the MKB with a full read_file of the ~128 MiB MKB_RO/MKB_RW allocation, which fails on file-backed readers — leaving the MKB empty, so Disc::inputs() shipped mkb=0 to an online key service and the request was rejected (no key → no decrypt). Scan now reads the MKB through the same bounded prefix-grow + trim reader as the out-of-band path, so Disc::inputs() is the single complete source of AACS inputs — one reader for every caller.
• Read-time key-fetch parses Unit_Key_RO.inf at the disc's own AACS stride. The on-demand fetch (for a CPS unit not sampled up front) hardcoded the V20 64-byte stride, so an AACS-1.0 (V10) disc whose key arrived as a VUK derived the wrong unit keys. DiscInputs now carries the disc's version, and the context parses at the matching stride — the disc is the single source of truth for its own stride (no separate version argument to drift).
• A dry key-fetch for one unit no longer blocks fetching a different unit. A global "fetch spent" latch meant that once the key service returned nothing for one CPS unit's ciphertext, no further unit was ever asked — so a multi-CPS disc could strand a unit whose key the service would have served. Replaced with a per-unit "already-asked-dry" set (still bounded by the fetch budget).
• verify::push_ranges uses saturating arithmetic so a corrupt-disc LBA near u32::MAX can't panic (matches udf::merge_ranges).

[1.1.0]

Added

• Post-read decrypt-verify gate. Every AACS unit read off the disc is now buffered, re-aligned to its clip-file 6144-byte unit grid, and verified (CPI flag → decrypt → strict all-32 TS-sync, matching libaacs _verify_ts) before it is signed off as good. A unit that neither a held nor a freshly-fetched key decrypts is treated exactly like a bad read — re-read by the patch pass, terminal loss only if truly unrecoverable — closing the "silent bad read" class where a sector reads OK but its ciphertext is subtly wrong. Fail-safe: it only ever downgrades a unit it is confident is bad; every uncertainty (no keys, a merely-missing key, an unread/zero-filled sector, a non-AACS disc) leaves the read byte-for-byte as before. Gated by a compile-time kill-switch (POST_READ_VERIFY), and container-pluggable (BD/UHD transport stream today, with an HD-DVD program-stream seam in place).
• Every error is now Error: E<code> <message>, with an Error Codes reference. User-facing errors show their code so you can look it up, and a new Error Codes page lists every code with its message, cause, and next steps. A contract test guarantees every error variant has a code, a message in all seven languages, and a Codes-page entry. Messages are source-agnostic ("key source", never a specific database).

Changed

• AACS decrypt acceptance is now standards-strict. A key is accepted only when the decrypted unit has the TS sync byte on all 32 source packets (libaacs _verify_ts), replacing a majority-vote heuristic where a wrong key could coincidentally restore enough syncs to pass and silently corrupt a unit.
• keydb download/save moved out of the library into freemkv-keysources; libfreemkv no longer has any keydb I/O (it already held no keys).

Fixed

• AACS content-certificate bus-encryption flag read from the wrong bit. The flag is bit 7 of byte 1 (libaacs p[1] >> 7) but was read as bit 0, so a bus-encrypted disc parsed as not bus-encrypted — defeating the fail-loud guard that refuses to decrypt bus-wrapped data to garbage when no bus key was obtained. Also corrected the cc_id offset (byte 14) and the AACS2 type marker (0x10). Confirmed against real retail content certificates.

• DVD rips now start on the movie, not the disc menu. A VTS title VOB's start sector was read from the IFO as a VTS-relative pointer but used as an absolute disc address, so a DVD title's read extents began ifo_lba sectors too early — the rip opened on the disc's menu / VMGI region and only drifted into the feature minutes later (Silence of the Lambs, for example, showed several minutes of the main menu before the movie). The title VOB is now rebased to its absolute on-disc location, so the rip begins at the first frame of the feature. Aspect ratio and chapter timing were already correct; only the starting sector was wrong. (Covered by a new absolute-placement regression test.)

• Container metadata correctness. Unknown colorimetry now emits the CICP "unspecified" code point (2) consistently across the MKV track and the FVI sidecar (previously 0); PGS subtitle wipes use the NORMAL composition state rather than a full epoch reset; and FVI source-byte offsets are written within-sector per the format spec.

• Multi-extent AACS alignment in dir:// extraction. AACS encrypts in aligned units of 3 sectors (6 KiB), and the decrypt-on-read gate accepts a read only when its LBA is unit-aligned against a base. The dir:// file-tree extractor set that base once, to the file's first extent. A fragmented file (Long-AD / continuation-ICB allocation) has later extents starting at arbitrary LBAs whose distance from the first extent is generally not a multiple of 3 sectors, so the first read of every later extent failed the gate, returned a decrypt error, and the whole extent was written as a zero-filled hole — even though the sectors were readable. The unit base is now re-anchored per extent (matching the mux read paths), so each extent gates on its own unit grid. Decryption math is unchanged. Same class as the rc.5.2 clip-anchor fix.

• Distinct "no key" reasons. When AACS key resolution has usable material (device or processing keys) but cannot obtain the disc's Volume ID — needed to derive the unit key — freemkv now reports a distinct "AACS Volume ID unavailable" error (E7017) instead of collapsing it into the generic "no key" error (E7022), which is now reserved for a genuine absence of any key material. No key derivation or descramble logic changed — only the reason reported on a resolution failure.

• autorip keydb writes go to the right path. Auto-download, daily refresh, the "Update KEYDB" button, and the startup existence-check now resolve to the service's config path (matching where reads look); they previously used the CLI's executable-local default.

• Crash-safety hardening in dir:// extraction and keydb writes (fsync of files and parent directories around rename).

• Windows-reserved filenames (CON, NUL, COM1…) inside a disc's file tree are safely renamed on extraction instead of aborting the walk.

• --version now matches the build stamped into MKVs. The CLI's --version string and the MuxingApp / WritingApp fields written into every MKV now derive from a single libfreemkv constant — the package version plus the git short hash (e.g. freemkv 1.1.0 (g835cc99)). The muxer previously kept its own copy of that string, so the two could drift; a binary and the files it produces can no longer report different versions.

• DTS-HD Master Audio: a false core-sync inside the lossless extension no longer splits an audio frame. A byte pattern in the extension substream that resembled the 0x7FFE8001 core sync word could truncate the lossless extension and produce decode errors on the affected frames. The extension substream is now sized exactly from its header, so that pattern is skipped as data.

• TrueHD: decode timestamps no longer step backward. In a case where the source PES timing lagged the audio access-unit cadence, the muxed decode timestamp could regress (non-monotonic-DTS warnings to the muxer); the running timestamp is now clamped so it never goes backward.

Tests

• 58 new tests across the toolchain (AACS key resolution, the unlocker seam, the key sources, DVD/CSS, dir:// routing, and autorip keydb resolution).

[1.0.0-rc.5.3]

Added

• dir:// output — write a decrypted VIDEO_TS / BDMV file tree straight from a disc or ISO instead of a single muxed file.

Changed

• Source-agnostic key errors — decryption messages no longer assume a local key database is the key source.
• The default keydb.cfg location is next to the executable (portable CLI); the autorip service keeps its container path.
• Simpler flags — dropped -k (use --keydb) and removed --device (the drive is named in the source URL, e.g. disc:///dev/sgN).

Fixed

• Fail loud on missing keys or bad input instead of silently writing an undecrypted file.

[1.0.0-rc.5.2]

Fixed

• Reverted the rc.5.1 DefaultDecodedFieldDuration experiment for interlaced SD-DVD. rc.5.1 added a 20 ms DefaultDecodedFieldDuration field element to the 576i/480i track header on the theory that Windows derives fps from it. Captured evidence showed that element made Windows Explorer report 12.5 fps (half) and MediaInfo flip the track to "Frame rate mode: Variable", while MakeMKV's rip of the same disc omits it. The element is therefore no longer written (MkvTrack::video now passes field_duration_ns == 0); the track keeps FlagInterlaced=1 + FieldOrder=TFF and the full-frame 40 ms DefaultDuration (1/DefaultDuration = 25 fps), matching MakeMKV. How a given player or shell handler chooses to display interlaced fps is not guaranteed.
• Correct AC-3 audio track selected on DVDs with non-standard sub-stream ordering. freemkv assigned each declared audio stream a physical sub-stream by ordinal (0x80+n), assuming the IFO's first stream lives at 0x80. On discs where the 5.1 main mix sits on a different sub-stream and 0x80 carries a 2.0 down-mix (e.g. Silence of the Lambs), the 2.0 was muxed under a "5.1" label. freemkv now probes each physical sub-stream's actual channel count from the disc — scanning every AC-3 frame and taking the maximum, so a brief 2.0 logo bed at the feature head can't mask the real 5.1 — and routes each declared stream onto the sub-stream that genuinely matches.
• "Decryption failed" on large AACS Blu-ray titles fixed. AACS encrypts in aligned units of 3 sectors (6 KiB); the unit-alignment gate measured lba % 3 against absolute disc LBA 0, but the unit grid is actually anchored at each clip's encrypted-region start. A clip whose start is not 3-sector-aligned had its readable units wrongly rejected — failing the feature/large titles of some discs while short clips passed. The gate is now clip-anchored.
• Single-pass disc→MKV recovers marginal/transient sectors before failing. The direct-to-MKV path now gives the drive its full ECC recovery budget on a bad sector (matching the multipass rip) instead of reporting a read failure a multipass rip would have recovered.
• 4K decode glitches at non-seamless clip joins fixed (Top Gun class). Titles assembled from clips joined at non-seamless boundaries no longer drop reference frames at the join ("Could not find ref" stutter); the splice keyframe is rewritten so the decoder discards only the genuinely-dangling leading pictures.

Changed

• freemkv-keysources is now a pure key lookup. The encrypted content-sample reader and the candidate-key resolution loop moved into libfreemkv (they read the disc and validate keys — decryption mechanism, not lookup). A key source now only looks a key up and hands it back. Downstream API: use libfreemkv::read_encrypted_units / libfreemkv::resolve_and_apply (was freemkv_keysources::read_sample_units / …::resolve_and_apply).

Added

• --log-level 3 is now self-sufficient for MKV/opening-frame diagnosis. The diagnostic pass now (a) dumps the ACTUAL MKV TrackEntry elements written per track (tag=mkv.track: FlagInterlaced, FieldOrder, DefaultDuration, DefaultDecodedFieldDuration via field-duration, Display dims, codecPrivate as hex) so the Windows-fps-class metadata is verifiable from a log alone, and (b) captures the first ~100 coded frames per track (raw bytes) to a <output>.opening.bin side file with a per-frame summary line (tag=mkv.opening.frame: track, key/delta, size, PTS) so opening-GOP / menu issues are diagnosable from a future log without the disc. Both are gated to log-level 3; a normal run opens no side file and records nothing.

Verified

• DVD opening-GOP / still-frame open handling is correct (no change needed). The hypothesis that the opening pictures get the wrong (last-seen) sequence header or have their PTS floored to t=0 was traced and ruled out: the codecPrivate is the FIRST sequence header (read once at headers-ready, before any later AU), DVD VOBU structure guarantees each title opens on a sequence header + I-frame (no mid-GOP open), the parser back-anchors leading still-frames to the disc's real timeline, and the muxer anchors its timestamp base on the opening keyframe's real PTS so the t=0 floor never corrupts it. Regression tests pin all three.

[1.0.0-rc.5.1]

Fixed

• CSS reads unlocked on enforcing drives. CSS-protected DVDs on drives that enforce CSS authentication previously produced an empty MKV at exit 0, or hung indefinitely. The read path now issues the bus-auth handshake (css::auth::unlock_css_reads) to unlock scrambled-sector reads before attempting any data transfer, so the drive gates lift correctly.
• Keyless title-key recovery always runs. The Stevenson known-plaintext attack (css::crack_key / src/css/stevenson.rs) now recovers the title key even when the bus-auth scan detects a CSS drive, removing a code path that fell through to locked reads on certain disc/drive combinations. A wrong key still fails cleanly (confirmed by a sector descramble check) rather than producing silent garbage.
• Early bail on undecryptable discs. When CSS authentication succeeds but no valid title key can be recovered, the mux path now terminates with a clear error code instead of writing an empty (or zero-byte) output file.
• DVD audio channel count from AC-3 bitstream. The audio channel count is now parsed from the AC-3 elementary-stream bitfield rather than from the IFO audio attributes, so the reported channel count always matches the actual muxed audio even when the IFO attribute disagrees. Passthrough only — no downmix is performed. (Selecting the correct audio sub-stream on discs with non-standard ordering is a separate item — see Known issues.)
• Interlaced MKV frame rate on Windows. Interlaced content (576i/480i) now emits a DefaultDecodedFieldDuration element in the MKV track header, which Windows Media Foundation and Explorer use to derive the display frame rate. Without it, players reported an incorrect or zero frame rate on interlaced tracks.
• Per-track BPS bitrate tags populated. The BPS tag is written for each track so players and shell extensions (Windows Explorer, MPC-HC, etc.) can display the per-stream bitrate without reading the full file.
• Interlaced field order corrected to TFF. 576i tracks were written with a bottom-field-first (BFF) container flag that disagreed with the top-field-first order carried in the MPEG-2 stream; the MKV FieldOrder element now matches the stream (TFF) so deinterlacers use the correct field parity.
• DVD first-play menu no longer prepended to the feature. The title VOBS base sector was read from the VTS menu-VOBS pointer (vtsm_vobs, offset 0xC0) instead of the title-VOBS pointer (vtstt_vobs, 0xC4), so on a disc that authors a per-title menu the entire menu VOB — e.g. a studio first-play "the parental level has been set, press yes" prompt — was prepended to the movie and every cell extent shifted back. The rip now opens on the feature's first frame.

Changed

• AACS handshake skipped on DVDs. The AACS authentication sequence is no longer attempted on DVD discs (it never applied to CSS-encrypted media); attempting it on a DVD drive was a no-op at best and surfaced spurious errors at worst.

Added

• Structured disc diagnostics at --log-level 3. A new diagnostic pass emits structured log events at INFO level when the log level is 3 or higher: DVD PGC/cell layout and IFO video/audio attributes; BD/UHD playlist, clip, and AACS metadata. Provides a single-command snapshot for diagnosing mux or authentication issues without instrumenting the source.
• Reduced per-operation log spam. Mux-read and seek operations are demoted to TRACE (were DEBUG); benign navigation-packet drops are summarized as a single counter at the end of the title rather than logged per-packet.

Known issues

• Wrong audio track on discs with non-standard substream ordering. Audio sub-stream ids are assigned by per-codec ordinal rather than read from the IFO/PGC stream-number table, so a disc whose physical substream order diverges from the convention may select the wrong audio track (e.g. a 2.0 stream in place of 5.1). Diagnose with freemkv info disc://… --log-level 3; fix tracked for the next release.

[1.0.0-rc.4.2]

Fixed

• Windows durability. New platform-aware io::fsync module: directory fsync is a no-op on Windows (std cannot open a directory there, which logged a spurious warning on every mapfile write — including from the CLI), and a shared file_durable helper opens files read+write before sync_all so the flush succeeds on Windows, where FlushFileBuffers rejects a read-only handle with ERROR_ACCESS_DENIED.

[1.0.0-rc.4] — UNRELEASED

An audit-driven round of correctness, durability, and Windows-transport fixes. No API changes; behavior is more conservative on damaged media and on partial decryption.

Fixed

• Decrypt-time loss is accounted for. A partial AACS/CSS decryption failure can no longer pass as a perfect rip — skipped/undecryptable bytes are folded into the loss total — and partial CPS-unit (per-title) key coverage is rejected in the AACS validation gate instead of producing partly-garbage output.
• Durable writes. keydb.cfg is written atomically (temp file + fsync + rename), and the mapfile fsyncs its parent directory after the rename so a resume checkpoint survives a crash.
• Truthful error causes. A server-dropped keydb download is classified as a connection error, not a parse error; a missing home directory maps to "not found" rather than a keydb-parse failure; the I/O error from opening an AACS-inputs ISO is preserved; and a transport failure is preserved through the AACS auth handshake instead of being relabeled.
• A failed READ CAPACITY now warns instead of silently using a zero-sector disc.
• A leaked pipeline consumer can no longer finalize an abandoned output.
• Windows SCSI. ScsiPassThroughDirect is packed to match the ntddscsi.h layout, StorageAdapterDescriptor.BusType width is corrected (u8 → u32), oversized read batches on non-sysfs (Windows) drives are bounded, IOCTL_STORAGE_RESET_DEVICE failures are surfaced, and a device reset only sleeps on success.
• Mux now tracks skipped bytes so a partly-read title reports accurate loss.

Changed

• The per-read Drive::read trace event was demoted to TRACE so a debug log isn't flooded by per-sector reads.

[1.0.0-rc.2]

Second release candidate for 1.0. libfreemkv is the core library: disc scan, multipass sector recovery, content decryption (CSS, AACS 1.0/2.0), and the threaded mux pipeline that turns a disc or ISO into an MKV. This candidate adds keyless DVD/CSS support and correct DVD video, on top of security and recovery hardening.

Added

• Keyless DVD/CSS title-key recovery. A CSS-protected DVD decrypts with no key database — the title key is recovered directly from the scrambled disc data via the Stevenson known-plaintext attack (ported from libdvdcss) and validated by descrambling a sector and confirming the known plaintext reappears, so a wrong key fails cleanly instead of producing silent garbage (src/css/stevenson.rs). Disc::scan_image recovers the same title key from a raw, still-scrambled CSS ISO, so a raw image can be muxed without pre-decryption.
• MPEG-2 Program-Stream access-unit reassembler (src/mux/codec/mpeg2.rs). Buffers elementary-stream bytes across PES packets and emits exactly one coded picture per MKV block, with presentation timestamps reconstructed from the stream — fixing corrupted DVD video. Bounded buffer so a malformed stream cannot exhaust memory.

Changed

• Self-contained keyframes: the active param sets (HEVC VPS/SPS/PPS, H.264 SPS/PPS, VC-1 sequence/entry headers) are re-asserted at every keyframe and any mid-title param-set change is emitted in-band, fixing whole-segment HEVC/H.264/VC-1 corruption when a source stops repeating or reverts a param set.
• Block timestamps use presentation order keyed on track type, so B-frame video (including a Dolby Vision enhancement layer) keeps its true presentation timestamps instead of decode-order timecodes.
• Mux unit alignment is scheme-aware (AACS vs CSS/none), so DVD extents are no longer rejected for unit misalignment.
• MKV output records freemkv <version> in the Muxing/Writing application fields, so every output file is traceable to its build.
• Subtitle BlockDuration values are scaled by the segment timecode scale, so display durations are correct when the scale is not 1 ms.
• The NOT_READY retry pause in the patch (Pass N) loop is halt-responsive: a stop request interrupts the drive-recovery wait immediately instead of blocking shutdown.
• Bounded the keydb decompressed-plaintext reader (caps a malformed or zip-bombed download).

Fixed

• A READ(10) that returns GOOD status with a residual underrun is treated as a failed read (routed to retry) instead of committing stale buffer data — closing a silent-corruption hole in the sweep and patch paths.
• raw_command on Linux masks the DRIVER_SENSE bit before treating a result as an error, preventing false transport errors on commands that return sense alongside a GOOD response.
• READ CAPACITY (10) rejects the "capacity exceeds 32-bit" sentinel instead of silently wrapping to 0 and misreporting disc size.

Security

• Content keys (CSS disc/title keys, AACS unit/volume keys) are redacted in log output (logged as <redacted> with a 1-byte fingerprint); a test guards against any key field being logged with a raw value.
• The macOS SCSI shim uses posix_spawn directly instead of system() / sh -c, eliminating a command-injection vector on the device-path string.

[1.0.0-rc.1]

First release candidate for 1.0 — the first tagged 1.0 milestone of the core library. Established the full feature set: multipass sector recovery, content decryption (CSS, AACS 1.0/2.0) from keydb.cfg, disc parsing, and the threaded mux pipeline (see "Pre-1.0 development" for the consolidated feature list).

Pre-1.0 development

Versions 0.x were the iterative development series leading up to 1.0. The highlights, condensed:

• Multipass recovery engine. Pass 1 sweeps the whole disc sequentially, tolerating bad sectors with an adaptive damage-jump algorithm (mark the bad range, keep going). Pass N retries the bad ranges with per-sector recovery timeouts, reverse-direction reads, and range bisection. A mapfile tracks per-sector state across passes so a rip can resume.
• Drive and SCSI layer. Single-shot, synchronous SG_IO transport on Linux (with IOKit on macOS and SPTI on Windows), full SCSI sense decoding, and drive enumeration / presence probes. Single-shot reads by design — recovery lives in the multipass orchestration, not inline in the read path.
• Content decryption. CSS for DVDs and AACS 1.0/2.0 for Blu-ray and UHD, with keys read from keydb.cfg. A single decrypting decorator wraps the sector source so decryption is one audited surface, and a resolved key is verified against disc content before it is applied.
• Disc parsing. UDF, MPLS/CLPI (Blu-ray), and IFO (DVD) parsing for title and extent assembly, with bounds checks on values derived from untrusted disc input. Canonical main-title selection picks the real feature over a play-all virtual playlist on branching discs.
• Mux pipeline (the "highway"). A three-stage threaded pipeline — read+decrypt, demux, codec parse — with a recycled buffer pool, taking file-backed mux from ~60 MB/s to several hundred MB/s warm-cache. Codec parsers for HEVC, H.264, VC-1, MPEG-2, TrueHD, DTS(-HD), and PGS feed an EBML/Matroska writer.
• I/O stack. Bounded-cache writeback (sync_file_range + posix_fadvise(DONTNEED)) keeps the kernel dirty-page cache bounded on long sequential writes, and time-batched mapfile persistence keeps NFS-staged rips fast.
• Library hygiene. No user-facing English in the library — all errors are numeric codes handled by the application layer. A large spec-grounded, mutation-verified test suite guards the silent-corruption surfaces. Rust 2024 edition; release builds use thin LTO.